CD/DVD

It's hard to imagine that in the 1980s the first CD players cost thousands of dollars and were the province of only the wealthy and rabid audiophiles. Today compact discs and compact disc players are found in virtually every environment imaginable—from the home to the workplace to the classroom. They're inexpensive and they are the closest thing we have to a universal format for music media (although the MP3 format is rapidly catching up).

Digital versatile discs (you probably know them better as DVDs) and their players are in much the same situation as CDs and CD players were in the '80s and early '90s. Just as the CD virtually eliminated the demand for vinyl records, so too has the DVD begun to cut deeply into the sale and rental of videocassettes. When recording to the DVD format becomes more affordable, you can be sure that VCRs will disappear entirely.

While CDs and DVDs are best known as entertainment media (for listening to music and watching movies, respectively), you'll see that both media are capable of storing all kinds of information. Click on the questions below to learn more about how CD/DVD technologies work and how they can be used in learning environments.

1. How do CDs and DVDs actually work?
2. What can CDs and DVDs be used for?
3. What are some educational uses for CDs and DVDs?

What can CDs and DVDs be used for?

Both DVDs and CDs are intended to be used as storage media. When you buy an audio CD in a record store, you're essentially buying stored musical information that you can access by means of a CD player. When you buy a DVD movie, you're buying access to previously stored images and sounds. In the early 1990's CD-ROM (that is, CD-Read Only Memory) technology became popular with computer users. The CD turned out to be a great medium for the sale and distribution of computer software. Most software continues to this day to be distributed by CD-ROM. While there currently isn't a lot of software available in the DVD format, you can be sure that when software programs get too big even for CDs, DVDs will be there to take over.

When recordable CDs and DVDs were introduced (in the mid and late 1990s, respectively) both formats became even more popular with home computer users. Important programs and files could be easily backed up onto compact disc, audio CDs could be easily duplicated with CD "burning" software, and home video aficionados could upload their digital home movies to computer for editing and then transfer the completed video to DVD.

You should know that there are different kinds of recordable CDs and DVDs:

• CD-Recordable (CD-R) lets users permanently burn data to disc.


• CD-ReWritable (CD-RW) lets users erase data and write new data to disc.


• DVD-Erasable (DVD-E) permits multiple data recordings.


• DVD-Recordable (DVD-R) lets users permanently burn data to disc.

Scratched or otherwise unusable DVDs and CDs make good drink coasters; they can also be used in arts and crafts projects. While it's pretty difficult to break them, shattered discs can produce sharp, pointed edges - so keep them away from children.

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